I can't really see what he's supposed to have done wrong.

The man goes out to a country where the regime in power is in fact one which has been armed and supported by the USA, gets recruited by the organisation that is ruining the place. Not a regime I like, but that's not relevant. Right, he's in uniform, insofar as they have uniforms. Probably does some fighting in the civil war against the Northern Alliance that has been going on for ever. But in no sense did joining the Taleban mean that he was taking up arms against the USA.

Then the Americans get involved, after September 11th, which noone suggests was a Taleban operation. The only reason they came into the picture was that they refused to hand him over, which may have been foolish, but wasn't an act of war in itself.

So the Americans respond by getting into the war in support of the Northern Alliance - but they aren't exactly in range of a foot soldier with a gun, even if he wanted to take up arms against the, They are dropping bombs and sending missiles and so forth. The actual fighting is still against the Northern Alliance. It doesn't seem particularly likely that an ordinary foot soldier would ever have come up against any of the relative handful of non Nor then Alliance ground soldiers, American or British or whatever.

Then he gets captured and taken at a holding facility where a confusing time was had by all, and large numbers of prisoners were killed during and following a mutiny. And an American is killed by some of them - no suggestion that John Walker has any involvement in this either.

And then he turns up as one of the handful of survivors.

What's he supposed to have done that was wrong?